Transmission



Nov. 2, 1937. D. s. BENNETCH 2,097,436

TRANSMISSION Filed May 26, 1933 9' Sheets-Sheet 1 Inventor Ja /ad. 367172.920 a Nov. 2, 1937.

D. s. BENNETCH 'mlmsmssion Filed May 26, 1933 INTERMIDIATB f'ram Idle an m to myh.

JH|GH= Mechanical cluzcb enyayed.

I I 9 Sheets-Sheet 2 INVENTOR DAV/'0 5. BENNETC/l.

ATTORNEYS D. S. BENNETCH TRANSMISSION Filed May 26, 1933 9.Sheets-Sheet 3 Inventor Nov. 2, 1937.

Nov. 2, 1937. o. s. BENNETCH TRANSMISSION I Filed May 26, 1933 9 Sheets-Sheet 4 labia 5B6): rte/0k 'Nov. 2, 1937. o. s. BENNETCH TRANSMISSION Filed May 26, 1933 9 Sheets-Sheet 5 n M 1m u e m n y m 3 gm 5 w v ig i flllorney D. s. .BE NNETCH TRANSMISSION Filed na 26. 1933 .9 Sheets- 1 6 Nov. 2,1937.

D. s'; BENNETCH TRANSMISSION Filed May 26, 1933 I 9 Sheets-Sheet 7 m M A Nov. 2, 1937.

D. S. BENNETCH wnmsmxssxon Filed may 26, 1933 i 9 Sheets-Sheet e \m 1 RR Nov. 2, 1937. b. BENNETCH TRANSIISSION Filed llay 26, 1933 9 Sheets-Sheet '9 Patented Nov. 2, 1937 UNITED STATES PATENT OFFICE TRANSMISSION David s. Bennetch, Sheridan, Pa. Application May 26, 1933, Serial No. 673,086 I 12 Claims. (Cl. 0-53) This invention appertains to new and useful improvements in transmissions for motor vehicles of the type driven by internal combustion engines and the principal object of the present invention is to provide a transmission which will eliminate gear shifting and automatically control the ratio of speed change between the drive and driven shafts.

Another important object of the present invention is to provide a transmission of the fluid controlled type wherein the fluid under comprestransmission under compression can be used in conjunction with conventional fluid wheel brakes. These and various other important objects and advantages of the invention will become apparent to the reader of the following specification. In the drawings: Figure 1 represents aside elevational view of an internal combustion engine equipped with the novel transmission means.

Fig. 2 is a diagrammatic view of the transmission illustrating the positions of the swash plates and mechanical clutch between idling and high.

Fig. 3 is a diagrammatic view of the transmission illustrating the positions of the swash plates and mechanical clutch just previous to direct drive.

Fig. 4 is a diagrammatic view of the transmissionillustrating the positions of the swash plates and mechanical clutch for direct drive.

Figure 5 represents a vertical sectional view of the valve means inforward speed, this section being through the pump side of the valve at 5-5 of Fig. '7.

Figure 6 represents a vertical sectional vie through the valve as shown at 6- 6 in Figure 7, this section being taken through the outlet side of the valve.

Figure 7 represents a horizontal sectional view through the valve taken at 'l| of Fig. 38.

Figure 8 represents an elevational view of the front of the valve structure;

Figure 9 represents an elevational view of back of the valve structure.

Figure 10 represents a longitudinal sectional view through the piston blocks and valve drum.

Figure 11 represents a vertical sectional view taken substantially on line ll-ll of Figure 38.

Figure 12re'presents a vertical sectional view rod for.controlling the forward piston block.

the

taken substantially on line l2l2 of Figure 38.

Figure 14. s I Figure 16 represents a vertical sectional view 10 through the connecting rod of the forward ring and looking toward the said ring.

Figure 17 represents a vertical sectional view taken substantially on line l|--l|of Figure 38.

Figure 18 represents a fragmentary longitudinal sectional view through the governor controlled means.

Figure 19 represents a vertical sectional view taken substantially on line |9--l9 of Figure 38. Figure 20 represents a sideelevational view of. the piston ring controlling cam.

Figure 21 represents a side elevational of the drums controlling ring.

Figure 22 represents a cross sectional view taken substantially on line 2222 of Figure 21. Figure 23 represents a fragmentary elevational view of the drums controlling cam in high speed or direct drive position. I

Figure 24 represents a fragmentary elevational view of the drur'ns controlling cam, with the parts in low or intermediate speed position. Figure 25 represents a fragmentary elevational view of the cylinder block's controlling means in idling or neutal position.

Figure 26 represents a fragmentary top plan view of the drive shaft, with the slide rods mounted therein. i s Figure 27 represents a perspective view of the rod for controlling the rear piston block.

Figure 28 represents a perspective view of the view .9? he free. clutch plates. 55

Figure 35 represents a perspective view of the clutch throw bell crank.

Figure 36 represents a vertical sectional view through the slide cam shown in Figure 38.

Figure 37 represents a lay-out of the control valve.

Figure 38 is a side elevation, with parts broken away, of the entire transmission assembly.

Referring to the drawings wherein like numerals designate like parts, it can be seen that numeral 5 represents in Figure 1, an internal combustion engine. Numeral 6 generally refers to the novel transmission and numeral 1 represents the clutch pedal which also controls the brake.

Referring to Figure 38, it can be seen that this transmission 6 includes the casing headers 8-9, the bottom and side wall In and the removable coverplate ll. Extending through the front header 8 is the drive shaft i2, while extending through therear header 8 is'the driven shaft l3.

Briefly, it will be understood that the governor mechanism I4 is responsive to the speed of the drive shaft l2 and controls the pump pistons by means of the carrier or drive ring assembly, generally referred to by numeral l5, as well as to also serve to operate both of the piston blocks,

generally referred, to by numerals I6 and i1.

Numeral l8 generally refers to the valve drum between the piston blocks i6-l1 and this valve unit serves to regulate the flow of fluid from the pump block l6 to the motor block H,- the latter in turn driving the ring assembly, generally referred to by numeral l9, which in turn controls the clutch mechanism 28 in response to the speed of the vehicle.

Numeral 2| generally refers to the cam for controlling the clutch mechanism 28, while numeral 22 represents the cam for controlling the valve drum l8 and effecting a, braking action in the transmission.

The governor mechanisms will be first described in detail. This governor mechanism (Figs. 17 and 18) consists of a wheel 25 pinned to the drive shaft l2, as at 26, this wheel 25 being provided with a pair of diametrically located peripheral ears 21-21 to which the weight arms 2828 are pivotally connected, as at 28.

Each of these arms 28 is provided with a weight 30 at its free end. and each weight 30 is connected by a link 31 pivotally to a corresponding ear 32 on the-circumferential flange 33 of the sleeve 34, which sleeve is swivelly connected to the shaft l2 by having a cross pin 35 therein bearing into the circumferential groove 36 of the shaft l2. This sleeve 34, as is clearly shown in Figure 21, has a roller 31 mounted thereon and a slot, generally referred to by numeral 38."

Referring to the governor mechanism shown in Figure 1'1, it can be seen that coiled springs 38' are interposed between the arms 28 and the aforementioned plate 25 to normally maintain the said arms contracted so that they will not way 42 for the trunnions of the yoke 43.

expand lmtil a certain speed: of the shaft l2 has been reached.

Telescoping the sleeve 34 is the sleeve 39 which has the slot-way, generally referred to by numeral 40 therein and this slot-way 48 receives the aforementioned roller 31 on the sleeve 34.

This sleeve 39 has a head structure 4! which is circumferentially grooved to provide the channel- (See Figure 38.)

Diametrically opposite side portions of the drive shaft. l2 (Fig. 18) are provided with 1 11-.

gitudinally extending slots 44 and each of these slots receives a pair of slidable rods 4546, each of which is provided with a lug 41 (Fig. 28) at each of its ends. The slot 44 is provided with an extension 46 for accommodating the longer rod 45. The rod 46 controls the piston block !6, while the rod 45 controls the piston block l1 and as is clearly shown in Figure 18, as well as in Figure 19, there are two sets of these rods. 1

The slot-way 43 in the sleeve 39 controls the thrust of the sleeve 39 and the positioning of the pistons in the piston block 16 through the action of the ringassembly l5. When the roller 31 has moved from the position a to the position b, (Fig. 20), the ring assembly l5 has been moved from vertical to the position shown in Figure 2. As roller 31 moves from into :1;, ring assembly l5 goes back to vertical. This action is explained more in detail hereinafter.

When the roller 31 proceeds from a: to the'position 0 in the slot-way 40, the ring assembly I 5 has been removed from vertical to a greater slant and to the position shown in Figure 3.

When high speed of the engine has been reached and the ring I5 and piston block 16 are to return to the position shown in Figure 4, the roller has reached the position d in Figure 20.

For positively actuating the piston blocks l6 and I1, it can be seen that the forward lugs 41 of the long and short rods 45 and 46, which fit in the slot 38 of the sleeve 34, will be shifted by the actuation of the sleeve 34. Normally at high speed the lugs 41 will rest in the pocket 48 of the slot 38, this pocket 48 being provided with a shorter side wall 49 for the rod 46 than the side wall 50 for the rod 45 so that the shorter rod 46 I will operate primarily to place the piston or pump unit I6 in position against the control drum l8 so that the fluid can be sucked into the unit l6 where it is pumped through the control drum I6 and by the time it is ready to be forced into the unit 11, the rod 45 has acted to bring this unit l1 against the drum I8. The reason for engaging unit IS with drum l8 before engagement between unit 11 and drum I8 is to suck oil from the reservoir and leave opening for air to pass out of unit "5 and drum Hi. When both of the rods 45 and 46 of each pair have their lugs engaged in the narrow canal 52, the two piston blocks [6 and I1 are contacting the drum I8, as shown in Figure 2, and this is the low or intermediate speed position of the assembly.

One wall of'the canal 52 is continued straight into the pocket 53, while the other side wall of the pocket 53 is oflset, as at 54, to accommodate the lug 41 of the rod 46, so that while the rod 45 will be retained in a position maintaining the piston block l1 against the drum Hi, the piston block I6 can move away slightly from the drum l8 and this is the idling position of the mechanism. It is necessary to keep drum l8 and unit 11 in contact at this time to obtain braking pressure for causing the transmission to act as a brake.

Referring to Figures 10, 11 and 12, it can be seen that each of the piston blocks l6 and I1 relatively small and substantially rectangular;v

shaped opening 51 whereby each of the bores 56 can communicate with the drum l8 at the proper moment.

splinedat 58 to a sleeve 6| which is in turn rotatable on the drive shaft I2.

Brace members 59 (Figs. 5, 6, 8 and 9) support the drum I8 in the proper'stationary position within the casing I9 and this drum has a hub 89 of sufficient passageway to accommodate the sleeve 8| to which the piston block I1 is secured and a coiled compressible spring 92 which is interposed between the inner ends of the piston blocks I6 and I1 and this spring normally tends to urge the said blocks away from the drum l8. In Figure I9, the drive shaft I2 can be seen extending not only through the block I8, but also through the block I1 and its sleeve BI and it will further be seen in Figure that suitable packing rings 63 are provided on the opposite sides of the drum I8 for'cooperation with the said blocks I9 and II to prevent escape of the liquid utilized.

The ring assembly, generally referred to by numeral I5, in Figure 2, is clearly shown in Figures 13- and 14, the same consisting of an outside tiltable, stationary annulus 95 which is provided with openings at a pair of diametrically opposite horizontally spaced points to receive the smooth portions of pins 86 which are threaded as at 81, and threadedly disposed through the side walls of the casing I9. The outer ends of these pins 69 are provided with polygonal shaped heads 68, while jamb nuts 89 are provided thereon at the inside of the casing I9, whereby the position of the pins with respect to the annulus 85 can be fixed.

At one side of the annulus 95 an' arm I9 is provided, the same being provided with a head II which is provided with an opening sufliciently large to accommodate the corresponding pin 89 and which is positively secured to the annulus 95 by screws 12.

The inner ends of these pins 86 are provided ith rollers I3 which ride in the peripheral groove-way I4 of the ring 'l5 and as is clearly shown in Figure 14, the annulus 85 is provided at its upperportion with an auxiliary pin I9 which, at its lower end, is provided with a roller 11 disposed in the said groove I4. Another aux iliary pin I9 is located at the lower portion of the annulus 85. The member 18 at the inside of the ring I5 is shown connected atits ends to pins I16 journalled in ring I5, while the opposite sides of its intermediate portion receive the oppositely disposed trunnions I9-I9 on the hub I on the drive shaft I2. Figure 13 shows the front side of the ring assembly I5 and by referring to Figure '16, it can be seen that the rear side of the-ring I5 has a plurality of sockets 8I equi-distantly arranged thereon to accommodate the forward ball ends of the connecting rods 82, which connecting rods connect the corresponding piston 83 in the pump piston block I8.

A pivotal link'84 extends from the aforementioned yoke 43 cooperating with the governor sleeve 39, to the aforementioned arm'l9 to connect at the point 85 and as is further shown in Figure 38, an elongated rod 88- extends from the lower end of this lever or arm I9, that is, at the point 81 to extend through a guide 88 rearwardly of the block I1 and this serves to control the clutch mechanism, generally referred to by numeral 29. g

The rear ring assembly I9'is constructed identically the same as the ring assembly IS, the only exception being that there is a supplementaln'ng resetting cylinder 89 (Figs. 29 and 38) hay-5 ing a plunger 99 therein connected to an elongated rod 9I having a pivotal connection 92 at its rear end which tilts the ring I9 to start the action thereof when the rear piston-block I1 is brought into operation. The cylinder 89 which resets the ring I9 from vertical to the tilted position is in communication with the valve I 53 at all positions of the valve by means of a port, as shown in Figs. 29 and 38.

The clutch mechanism, generally referred to by the numeral 29, is of generally conventional form, the .same involving the two head plates 93-94 (Fig. 31), the plate 93 being connected to the sleeve 9| to which the rear piston block I I is secured, while the head plate 94 is secured by a pin 95 to the driven shaft .I3. Guide pins 91 bridge the plates 93-94 and extend through the slidable clutch plates 98. Pins 99 also extend through these plates 98, while clutch plates I99 are interposed )between the plates 98 and are splined to the drive shaft I2, as at I92. Levers, equal in number to the number of pins 99, are denoted by numeral I93 and are rockably supported, as at I94, each being provided with'an ofiset end I95 for engagement against the circumferentially grooved collar I98 splined to the sleeve 8|. The outer end of each of these levers I93 is connected to the corresponding pin 99 by a pin and slot connection I91 and as is clearly shown in Figure 31, each of these pins 99 'is provided with a stop collar I98 thereon between the plates 93-94, while interposed between each of these collars I98 and the plate 93 is an expansible coiled spring I99 which isretained under compression so that the plates 98 and I99,-

are separated by means of the collar I99 which is urged toward the plate 93 when the clutch is disengaged with the parts as shown in Figure 38.

- As is clearly shown in Figure 39, a shaft H9 is disposed horizontally in the casing I9 and carries a pair of levers I I I-I I I, each provided with a trunnion II2 for engagement into the grooved collar ,I96 of the clutch mechanism. An elongated arm II3 depends from the shaft H9 and is connected by way of the link Ill to the bell crank II5 which has a roller H6 at its free end and which is fulcrumed, as at 5'.

The housing of the rear ring assembly I9 has a lever I I8 (Fig. 3) extending therefrom. A

pivotal link connection II9 extends from this lever II 8 to a point I29 0n link H4 at or near which point the link, I2I also connects at one end. 38 for purposes of clearness.) The other end of this link I2I connects to the upper end of the swingable arm I22, as at I23, forming a toggle I assembly I 5.

For controlling the clutch manually and for utilizing the mechanism as a, brake and also for reverse action, a cam assembly, generally re- (These points are shown separate in Fig.

ferred-to by, numeral I26 (Fig. 38), is employed .and includes the cams 2I and 22. This assembly involves a guideway I2I for the pair of con-- nected blocks I28-I29 of thecams 22-2I, respectively, provided with cam faces I39, I39. I The roller IIG, of the bell crank H5 is engageable with the face 139 of the cam I 29 for manual operation of the clutch 29, when in high. It will be understood that when inhigh, if it is desired to stop suddenly, the brake pedal I will 4 be depressed, which slides'block I26 rearwardly operating bell crank lever II5, opening clutch 2,0 and tilting ring I9 from vertical to maximum slant. I

The face I30 of the cam I28, when actuated by foot pedal 1, operates the pin I32 of the valve drum I8 (Figs. 5 and 6'), the, construction of which will be described hereinafter.

Referring to the mechanism for operating the cam assembly I26, numeral I33 represents a shaft extending inwardly of the casing I and to whichan arm I34 is secured at its inner end. A pivotal link I35 is interposed between this arm I34 and the forward end of the cam assembly I26 and a coiled spring I36 serves to maintain the cam assembly normally urged forwardly, that is, to

the position shown in Figure 38 and against the stop I31.

The outer end of the shaft I33 is provided with the aforementioned clutch pedal 1, as shown in Figure l, and which also functions as a brake pedal. Furthermore, pedal I also acts as a reversepedal, that is, when the laterally disposed head I38 of the turn rod I38 is displaced from the path of the' foot pedal 1, and this may be managed by a suitable handle I39 on this rod I38., (See Figure 1.) In other words, only one manual control is employed for the entire transmission, including reverse action, as well as brake and clutch action.

As before stated, the piston block I6 and its associated mechanism serves as a pump for pumping oil or other fluid having a suitable level in the lower portion of the casing I0 under compression through the drum I8 and into the block I1, to the end that the pistons in the block I1 will operate. 0

As is clearly shown in Figures and 6,numeral I40 represents the cylindrical shell of the drum I8 and this is divided vertically by a partition I4I (Fig. dividing the interior of the drum into a pump side and a motor side. This drum, on the pump side, as shown in Figure 5, has an inlet tube I42 for the fluid and furthermore, this side of the drum has a vertically extending partition, I43 at right angles to the partition I. Thus the pump side of the drum is divided into the chambers I44 and I45.

The motor side of the drum (Fig. 6) has a partition I46 extending from the hub 60 downwardly to the lower portion of the shell I40, while a curved partition I41 extends from theupper portion of the hub 60 to meet the cylinder I48 slightly below an opening I49 therein. Thus the motor side of the drum is divided into the chambers I50and I5I. The opposite ends of the drum I8 are provided with segmental shaped openings I52, there being one of these openings I52 for each of the chambers I44, I45, I50 and I5I.

As is clearly shown in Figures 5 and 6, the cylinder I48 is substantially tangentially disposed with respect to the shell I40 and has a pistonlike hollow valve element I53 splined therein.

Numeral I54 represents the exhaust pipe' which is connected to the cylinder I48 at the openings I55I56 vertically spaced in the cylinder and corresponding to the elongated openings I51-I58 in the valve element I53. As is clearly shown in Figure 6,-the interior of the piston valve I53 is divided by the horizontal partition I59 into the upper chamber I60 and the lower chamber I6I. The aforementioned pin or cam rider I 32 shown in Figure 38, depends from this piston.

pivotal flnger 201 fulcrumed. as at 208. and a valve I53 and is capableof riding on the cam face I 30' of the cam 22 to regulate the position of the valve piston.

Figure- 37 discloses a lay-out of the piston valve wall. On the pump side, there is the elongated opening I62 which covers two positions of the three stages of thevalve, as well as the lower elongated opening I63.- The three positions of the valve I53 are forward, neutral or braking and reverse. These openings I62 and I63 are complementary to the short openings I64-I65 respectively of the cylinder I48 on the pump side, while. on the motor side of the piston valve is located the elongated opening I66 which will cover all three stages of the valve, which is complementary to the single stage opening I61 in the shell I 48, while above this is located the pair of single stage openings I68 and I69 complementary to the single opening I49 on the motor side of the cylinder I48. A coiled compressible spring I10, shown in Figure 38, serves normally to urge the valve piston I53 downwardly so that the rider I32 will engage the level portion of the cam assembly I26.

Assuming the control valve I53 is in position for forward motion as shown in Figs. 5 and 6, when the pump assembly I6 is in operation, it sucks fluid up through the inlet pipe I42 (see Figure 5) and transfers thesame from the chamber I44 through one port I52 into the cylinders of the pump block I6 which carry the oil around from one port I52 to the other port I52 through which the oil passes into the chamber I45 from where it passes out by way of the openings in the cylinder I48 and piston valve I53 at the lower chamber I6I to the motorside of the drum I8, at which side it enters the chamber I5I, where it acts on the pistons of the piston assembly I1, as shownin Figure 88.

The fluid is exhausted by way of the upper chamber I60 of the piston valve I53 and the exhaust pipe I54. Reverse operation of the mechanism takes place when the cam assembly I26 is shifted so that the rider I 32 reaches a point on flat top of -the face I30 of the cam block 22. This closes ports I63-I65, registers ports I62I64, registers ports I49--I69, ports I66-I61 remaining open, registers port I58 with its exhaust port I56, and closes ports I55--I51. This causes fluid to be sucked in at I42 and discharged into I45, through ports I62-I64 into chamber I60, thence through ports I49I69 into chamber I50 from which it entersthe cylinders of motor block I1 driving this- -;block as a motor in the opposite direction. This then discharges into chamber I5I out through ports I 66--I 61 into chamber I6I, thence through port I58 to exhaust.

When the rider I32 is half way up, the ports I63I65 are open, ports I62I64 are open, ports I66-I61 are open, but port I49 is closed, ports I55I51 are open and port I58 is open. In fact only one set of ports, namely, I49 is closed, but this causes the motor block I1 to lock. As the control valve moves from its lowermost position to the half-way position, the ports I49 are only part way closed, this causing a retarding action on the motor block I1.

On the cam block 22 is an extension 200 which 'has a seat I therein. Numeral 202 represents a lever fulcrumed, as at 203, to the casing I0 and provided with a laterally disposed arm 204 having a foot 205 which is in the path of the assembly I5 when the cam assembly I26 is operated. The lever 202 has a shoulder 206 adjacent its heel portion under. which is engageable the spring 209 serves tonormally. retain the heel 2I0 onthis finger 207 snugly against the top of the block 22.

, The function of this eirtensio n 200, arm 204 and finger 201 is to retain the brake in fully applied position and to release this brake automatically upon speeding up of the engine drive shaft I2. In

operation, when the foot pedal I is operated, the

cam assembly I26 is shifted rearwardly and the pin I 32 rides up the inclined surface I30. As the pin I32 reaches the half way position on this inshoulder 206. This will retain the heel 2I0 engaged in the seat 20I, with the brake fully applied, or for parking purposes. All that is required in disengaging this brake retention means is to speed up the engine, which causes a movement of the assembly I5 from its upright position to its tilted position and in this movement engaging the foot 205 to shift the arm 204 so that the shoulder 206 will disengage from the finger 201 and permit the cam block I26 to regain the po-' sition shown in Figure 38. Thus the brake is released.

As shown in Figure 38, a rocker 220 is pivoted midway its length on the casing I0. A link 22I connects'one end of this rocker 220 and has a roller riding in an annular slot 220 on the block assembly I 'I'. The roller on link-22I is held in the slot 220' on the block II by a suitable support 22I' extending out from the casing. A link 222 block I6, the car is stationary.

connects the other end of rocker 220 tothe clutch.

yoke III, so that when the brake is applied and the clutch is disengaged, the rearward motion of the yoke I II will shift the rocker so that forward motion will be transmitted to the block assembly I'I, pushing the latter against the drum I8.

Assume that the engine is idling with the brake on and the transmission is in neutra The parts will take the position shown'in Fig. 38. Governor I4 has not yet started to operate so that the roller 31 is in the position a in Fig. 20, causing the forward ring I5 to be in vertical position. The long and short block-operating rods 45 and 46 are in the position shown in Fig. 25 causing the pump block I6 to be spaced from valve drum I8 to insure absence of any pumping action. Motor block I I contacts valve drum I8 and. rear-ring I9 is in the full inclined position, but since there is no pumpingaction of pump To start the car the engine throttle is opened, causing the governor I4 to operate sufficiently to move roller 3'! through position b to at, this serving'to kick to inclined position the forward ring I5. The engagement of ring I5 with foot 205,v

releases the cam block assembly I26 in case the brake happens to be on. The slot 30 does not move sufiiciently to engage pump block I6 with valve drum I8.

As the engine throttle is opened still wider, the roller 31 moves from position :1: toward c causing the car to gradually pick up speed. This causes the forward ring I5 to gradually incline from vertical to full tilt position. As roller 3'I leaves point :1: towards c, the slots 38 cause the pump drum I6 to engage valve drum I8 (Fig. 24). As the forward ring I5 tilts, the pumping action increases, causing the car to pick up speed.

After the car has picked up speed and the engine is moving sufficiently fast, the roller 31 reaches 0 a which point the ring I5 has full tilt ing action, as explained above.

At the same ltime "slots 38 have moved'tofth eposition shown 'i'niFig' 23, causing, fir'stfi motor block I1 and then pump block I6 to'separate from valve drum I8. This' releases pressure in both pump and motor blocks as well as in resetting cylinder 89 which allows therear ring. I9'to take its vertical position. j

Furtherincreaseof engine speed causes roller 3'! to go from cto d, causing the forward ring I5 to take vertical position. Thus the transmis sion is in high withfdrivingand driven shafts mechanically connected, with both forward and rear rings I5 and I9 vertical and with both pump and motor blocks I6 and I1 spaced from'valve" drum I8. This reduces movement and friction o'f the transmission parts to minimum. I To shift to a lowerspeed, the engine is permitted to slow down to just above the control speed corresponding to a vehicle speed-of, say, 22 miles an hour. As' the engine slows down to control speed (which we may assume to be 20 miles an hour) the roller 31 moves from d to 0, thus forcing forward ringfl5 to full tilt. At about; this time, movement of slots 30 causes the pump and motor blocks I6 and I1 to contact valve drum I8. Pressure is then built up in pump block I6 and transmitted to motor block I1 and resetting cylinder 89. The latter causes rear ring I9 to move to full tilt position, disengages clutch 20, and resets the toggle I2 I- '-I22. It will be, understood that the link II4 is mounted in, such a manner between bell cra'nk lever I I5 and arm II3 that, when moved rearwardly by rear ring I9, it straightens toggle I2I'I22 in which positon the latterfis held by toggle spring I24; Thus an intermediate speed drive is obtained, the ratio of which depends on the position of forward ring I5. I g I To apply the brakewhile in ".h'ighflithe foot pedal I is depressed, moving cam assembly I26. This operates twodevices, one, hell 'c'rahkl I5 and, two, follower I32. Asthe bell crank H5 rides up cam surface I30 it disengages clutch 20', moves -,rear ring I9 from vertical to full tilt position,

moves piston valve I53 to gradually close appropriate ports, as explained above, thus givin'g'a gradual braking. action until the appropriate ports are closed at which point the car is locked.

To reverse the car, handle I39 is operated, permitting'pedal 'I to be depressed further. This causes the follower I32 to ride further up .cam I30, moving piston valve I53 to give the revers- While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from thespirit and scope of the invention as claimed hereinafter.

Having described the invention, what is claimed as new is:

1. In a variable speed transmission, a stationary casing, a driving shaft in said casing, a driven said pistons and said swash plate, one ofsaid swash plates and its corresponding cylinder block being secured to said driving shaft, the other of said swash plates and its corresponding cylinder block being secured to said driven shaft, a mechanical clutch between said shafts, said cylinder blocks being located between said tiltable housings, a stationary valve 'drum between said blocks, a control valve insaid valve drum, means for shifting said valve to selective positions driving said motor unit ahead, in reverse, to lock said motor unit'or to exert braking effort to said motor unit, means for varying the relative tilt between said housings to change the speed ratios, and means whereby both said housings occupy erect positions and said mechanical clutch engages for direct. drive.

2. In a variable speed transmission, a stationary casing, a driving shaft in said casing, a driven shaft, a pump unit and a motor unit in said casing, each unit comprising a cylinder block,

.a plurality of pistons in said block, a tiltable housing pivoted to said casing, a swash plate iournalled in said housing, and connecting rods connecting said pistons and said swash plate, one of said swash plates being secured to said driving shaft, the other of said swash plates being secured to said driven shaft, a mechanical clutch engageable between said shafts, said cylinder blocks being located between said housings, a stationary valve drum between said blocks, a cylindrical piston valve in said valve drum, means for shifting said valve to selective positions for driving said motor unit ahead, in reverse, to lock said motor unit, or to exert braking effort on said motor unit, means for shifting said blocks with respect to said valve drum to kill pressure, said tiltable pump housing occupying an erect position and said tiltable motor housing occupying a full tilt position'for neutral, said pump housing occupying various angles of tilt to full tilt position with said motor housing in full tilt position far various speeds up to direct drive, and means whereby both said housings occupy erect positions and said mechanical clutch engages for direct drive.'

3. In a variable speed transmission, a variable stroke motor unit and a variable stroke pump unit, each unit comprising a set of cylinders and a tiltable swash plate cooperating therewith, said pump unit being driven by a source of power and said motor unit driving a load, a governor responsive to change of condition of said transmission, means for transferring fluid from one set of cylinders to the other, power devices controlled by saidgovernor for tilting the pump swash plate from erect position to full oblique position for varying the speed of the motor unit from zero to -maximum, the motor swash plate occupying a full oblique position for all speeds from zero to maximum, and power devices controlled by said governor for mechanically connecting the pump unit and the motor unit and for tilting both said swash plates back to erect position for direct drive.

4. The combination according to claim 3 in i which the governor is responsive to the speed of rotation of said pump unit.

5. In a variable speed transmission, a motor un t and a pump unit, each comprising a rotary and means controlled by said brake element for throttling the fluid compressed by the motor unit to obtain braking action.

6. In a variable speed transmission, a stationary support; a driving shaft on said support, a driven shaft on said support, a pump unit and a motor unit on said support, each unit comprising a cylinder block, a plurality of pistons in said block,'a tiltable housing pivoted to said support, a swash plate journalled in said housing, and connecting rods connecting said pistons and said swash plate, one of said swash plates being secured to said driving shaft, the other of said swash plates being secured to said driven shaft, a mechanical clutch between said shafts, said cylinder blocks being located between said tiltable housings, a valve casing between said blocks, a control device in said valve casing for controlling the rotational movement of said motor unit,

means for varying the relative tilt between said housings to change the speed ratios between said shafts, and means for bringing both said housings back to erect positions and for engaging said mechanical clutch for direct drive.

'7. In a. variable speed transmission, a stationary casing, a driving shaft in said casing, a driven shaft, a pump unit and a motor unit in said casing, each unit comprising a cylinder block, a plurality of pistons in said block, a tiltable housing pivoted to said casing, a swash plate journalled in said housing, and connecting rods connecting said pistons and said swash plate, one of said swash plates being secured to said driving shaft, the other of said swash plates being secured to said driven shaft, a mechanical clutch between said shafts, said cylinder blocks being located between said tiltable housings, a stationary valve casing between said blocks, a control valve in said valve casing, means for shifting said valve to selective positions driving said motor unit or looking said motor unit or exerting braking effort on said motor unit, means for varying the relative tilt between said housings to change the speed ratios, and means whereby both said housings occupy erect positions and said mechanical clutch engages for direct drive.

8. In a variable speed transmission, a variable stroke motor unit and a variable stroke pump unit, each unit comprising a rotary cylinder block and a tiltable swash plate rotating therewith, said pump unit being driven by a source of power and said motor unit driving a load, a governor responsive to changes of condition of the transmission, a stator between said cylinder blocks for transferring fluid from one cylinderblock to the other, a brake device in said stator, power devices controlled by said governor for tilting the pump said swash plates back to erect position for direct drive, and a manually governed brake element for tilting said motor swash plate from erect to oblique position and foroperating said brake device to throttle the fluid compressed by said motor unit thereby to cause said motor unit to act as a brake.

9. In a variable speed transmission, a variable stroke motor unit and a variable stroke pump unit, each unit comprising a rotary cylinder block and a tiltable swash plate rotating therewith, said pump unit being driven by a source of power and said motor unit driving a load, a speed responsive governor running with said pump unit, a stator between said cylinder blocks for transferring fluid from one cylinder block to the other, a brake device in said stator, power devices controlled by said governor for tilting the pump swash plate from erect position to full oblique position for varying the speed of the motor unit from zero to maximum, the motor swash plate occupying a full oblique position for all speeds from zero to maximum, power devices controlled by said governor for mechanically connecting the pump unit and the motor unit and for tilting both said swash plates back to erect position for direct drive, and a manually governed brake element for tilting said motor swash plate from erect to oblique position and for operating said brake device to throttle the fluid compressed by said motor unit thereby to cause said motor unit to act as a brake.

10; In a variable speed transmission, a motor unit and a pump unit each comprising a rotary cylinder block and a tiltable swash plate rotating therewith, a mechanical clutch for connecting said units, a transfer block between said cylinder blocks for transferring the liquid between blocks, means for holding said cylinder blocks in close engagement with said transfer block when power is being transmitted from one cylinder block to the other, and means for reducing friction between said cylinder blocks-and said transfer block when said mechanical clutch engages for direct drive.

11. In a variable speed transmission, a motor unit and a pump unit each comprising a set of cylinders and a tiltableswash plate, a mechanical clutch for connecting said units, a transfer element between said sets of cyilnders for transferring the liquidfrom one set of cylinders to the other, means for holding said sets of cylinders in close engagement with said transfer element when power is being transmitted from one set of cylinders to the other, and means for spacing. said sets of cylinders fromsaid transfer element when said mechanical clutch engages for direct drive,

said sets of cylinders and said transfer element being relatively rotatable.

12. In a variable speed transmission, a variable stroke motor unit and a variable stroke'pump unit, each unit comprising aset of cylinders and a controllable carrier ring cooperating therewith, said pump unit being driven by a source of power and said motor unit driving a load, 'a'governor responsive to change of condition of said transmission, means for transferring driving fluid from one set ofcylinders to the other, power devices controlled by said governor for moving the pump carrier ring from zero stroke position to full stroke position for varying the speed of the motor unit from zero to maximum, the motor carrier ring occupying a full stroke position for all speeds from zero to maximum, and power devices controlled by said governor for mechanically connecting the pump unit and the motor unit and for moving both said carrier rings back to zero stroke position for direct drive.

- DAVID S. BENNETCH. 

